On the Frame Properties of System of Exponents with Piecewise Continuous Phase

Abstract

<p style="text-align:justify;" class="MsoNormal"> <span lang="EN-US">A double system of exponents with piecewise continuous complex-valued coefficients </span><span lang="EN-US">are</span><span lang="EN-US"> considered. Under definite conditions on the coefficients the frame property of this system in Lebesgue spaces of functions is investigated. Such systems arise in the spectral problems for discontinuous differential operators.</span><span lang="EN-US"> <?xml:namespace prefix = o /><o:p></o:p></span> </p